I have a hitachi vtp-16a drill but it doesn't want to go on hammer action. Do I put the slider on 1 or 2 for hammer action? On both settings my drill has normal action, but sometimes between the middle or position 2 the motor turns but the chuck then doesn't turn. It is not a new drill, but it drills wood, etc. effortlessly. I am now trying to drill through a double brick wall, but it takes a very long time. I am using an 8mm concrete drill bit. Please help. Tx - Pieta